This invention is in the field of heat exchangers and more particularly heat exchangers for transmitting thermal energy from one moving fluid to another with specific application for gaseous fluid mediums. Typically heat exchangers comprise a plurality of adjacent passageways with relatively hot and relatively cold fluids in adjacent passages for facilitating the transfer of thermal energy from the hot fluid through the passage walls to the cold fluid. It is common for the hot and cold fluids to flow in opposite directions or in perpendicular directions designated counter-flow and cross-flow respectively; also in some cases the fluids flow in the same direction designated parallel-flow.
In the various apparatus there are a variety of design parameters which are selected in particular combinations to achieve various objectives, while necessarily sacrificing other factors, and in effect trading off one advantage for a different disadvantage. Certain of the most relevant parameters are thermal efficiency, pressure drop of the fluid through the passageway, manufacturing cost, rate of fluid flow through the device, and size and weight of the heat exchanger. Additional features that are relatively well known in the heat exchanger art include the use of a plurality of separate plates or sheets to define and separate the fluid passages, and sealing means for joining the various edges of these partitions to the housing and preventing leakage of the fluid between chambers or from the overall apparatus. A still further feature of heat exchangers is the requirement of some type of manifold inlet or outlet whereby hot fluids may be directed to specific passages, while cold fluids are directed to the various alternate passages in between the hot passages.
Assembly techniques for typical heat exchangers include welding, brazing, bonding, crimping, and the use of fasteners. In substantially all situations there is the complication of holding together in precise spaced relationship a great many individual pieces so that the multitude of passageways can be defined in a structure which is otherwise semi-rigid as a whole, and wherein there is sufficient strength internally to prevent the passageways or walls forming said passages from buckling or warping due to the heat extremes experienced on the opposite sides of partition walls and throughout the apparatus.